The more milk women drank in a new U.S. study, the less deterioration they experienced in their arthritic knees. It's not certain that milk was the reason for the slower arthritis progression, researchers said, and the effect was not seen in men. But the results add to evidence that nutrition may help to stave off arthritis. "Milk is an excellent source of vitamins and minerals, dairy calcium and protein and has long been recognized for its important role in bone health," Dr. Bing Lu told Reuters Health in an email.